The present invention relates generally to plumbing, and more particularly to electromagnetic bond welding of thermoplastic pipe distribution systems.
Plumbing systems for transporting water in residential, commercial, and industrial applications are conventionally based on copper pipe distribution systems. On a job site, a plumber typically pieces together a copper pipe distribution system by joining together two or more pipes via various fittings, such as couplers, elbows, tees, and crosses. A copper pipe may also be joined to various termination fittings, such as end caps, plugs, threaded adapters, and unions. The fittings themselves are typically fabricated also from copper, but other metals such as brass may be used.
In conventional practice, a copper pipe is joined to a fitting by soldering. The pipe is inserted into the fitting; the joint region is heated with a torch; solder is melted into the joint; the joint is allowed to cool; and the solder solidifies. Although copper plumbing has been widely used, it does suffer from a number of disadvantages. Creating a reliable joint requires proper preparation of the pipe and fitting (for example, removing dirt and oxide from the surfaces to be joined); heating the joint to the proper temperature range; applying the solder uniformly; and cooling the joint at the proper rate. All these operations are manually intensive and require a skilled operator (plumber). The soldering operation itself poses a potential fire hazard and releases fumes.
Alternative materials for plumbing distribution systems have been developed. One class of materials comprises thermoplastics, which are lightweight and have high chemical resistance. Fittings and on-site methods for quickly and reliably joining thermoplastic pipe are desirable.